#include <iostream>
#include <vector>
using std::cout;
using std::endl;
using std::vector;

void test0(){
    vector<int> nums{1,2,3};
    vector<int> nums2{3,8,9,7};
    vector<int> nums3{7,4,3,1,4};
    vector<vector<int>> Nums{nums,nums2,nums3};
    vector<vector<int>> Nums2{{3,8},{9,7},{6,7}};
    
    for(auto & vec : Nums){
        for(auto & i : vec){
            cout << i << " ";
        }
        cout << endl;
    }

    for(size_t i = 0; i < Nums.size(); ++i)
    {
        for(size_t j = 0; j < Nums[i].size(); ++j)
        {
            cout << Nums[i][j] << " ";
        }
        cout << endl;
    }

    for(vector<vector<int>>::iterator it = Nums.begin();
        it != Nums.end(); ++it)
    {
        for(vector<int>::iterator itt = it->begin();
            itt != it->end(); ++itt)
        {
            cout << *itt << " ";
        }
        cout << endl;
    }


 
}

int main(void){
    test0();
    return 0;
}
